CT-criteria for left atrium appendage thrombus detection

Abstract

Objective: Atrial fibrillation is strongly associated with stroke and accounts for 60% of cardioembolic stroke. Assessing thromboembolic risk is important for patients with atrial fibrillation. Approximately 90% of all thrombus are localized in the left atrium appendage (LAA). This study aimed to determine the efficacy of cardiac computed tomography (CT) for LAA thrombus detection. Material and methods: This retrospective study included 292 patients. LAA thrombus was confirmed or excluded by cardiac CT with the reference to transesophageal echocardiography (TEE). We excluded patients with allergic reactions to iodide, increased creatinine levels, thyroid disease (hyperthyroidism), pregnancy, and age <18 years. Results: According to the cardiac CT, 103 of 292 people had LAA thrombus, while according to TEE, only 48 of patients had LAA thrombus. The sensitivity and specificity of CT were 97.7% and 77%, respectively. The sensitivity and specificity of the CT was higher in 2016–2020, when the delayed phase was added to the standard protocol, compared to 2012–2015 years. Older age, higher BMI, higher CHA2DS2-VASc and HAS-BLED scores, and larger LA and LVESV were significantly associated with LAA thrombus detection on cardiac CT. Higher LVESV and LVEDV indexes (LVESVI and LVEDVI) and lower LV ejection fraction measured by TEE were also predictors of LAA thrombus detection by cardiac CT. Conclusion: Our findings show that cardiac CT has high sensitivity and specificity for excluding or confirming LAA thrombus, and can also be exclusively used to determine the presence or absence of a thrombus.

Keywords

• left atrium appendage thrombus
• cardiac computed tomography
• atrial fibrillation
• cardioembolic stroke
• transesophageal echocardiography